import 'package:flutter/cupertino.dart';
import 'package:please_pay_me/core/format/formatters.dart';
import 'package:please_pay_me/theme/theme.dart';
import 'package:please_pay_me/ui/ui.dart';

typedef ExpenseSubmit = Future<String?> Function({
  required double amount,
  String? note,
  required DateTime spentAt,
});

/// Modal form for a new expense. Submits through the caller so the sheet has
/// no knowledge of repositories.
class ExpenseFormSheet extends StatefulWidget {
  const ExpenseFormSheet({
    super.key,
    required this.onSubmit,
    this.budgetName,
    this.remainingToday,
  });

  final ExpenseSubmit onSubmit;
  final String? budgetName;
  final double? remainingToday;

  @override
  State<ExpenseFormSheet> createState() => _ExpenseFormSheetState();
}

class _ExpenseFormSheetState extends State<ExpenseFormSheet> {
  final _amountController = TextEditingController();
  final _noteController = TextEditingController();

  DateTime _date = DateTime.now();
  bool _saving = false;
  String? _error;

  static const _quickAmounts = [100.0, 250.0, 500.0, 1000.0];

  @override
  void dispose() {
    _amountController.dispose();
    _noteController.dispose();
    super.dispose();
  }

  double? get _amount {
    final raw = _amountController.text.trim().replaceAll(',', '.').replaceAll(' ', '');
    final value = double.tryParse(raw);
    return value != null && value > 0 ? value : null;
  }

  Future<void> _submit() async {
    final amount = _amount;
    if (amount == null) {
      setState(() => _error = 'Введите сумму больше нуля');
      return;
    }

    setState(() {
      _saving = true;
      _error = null;
    });

    final note = _noteController.text.trim();
    final error = await widget.onSubmit(
      amount: amount,
      note: note.isEmpty ? null : note,
      spentAt: _date,
    );

    if (!mounted) return;

    if (error != null) {
      setState(() {
        _saving = false;
        _error = error;
      });
      return;
    }

    Navigator.of(context).pop(true);
  }

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      backgroundColor: AppColors.of(context, AppColors.groupedBackground),
      navigationBar: AppNavBar(
        title: 'Новая трата',
        subtitle: widget.budgetName,
        leading: CupertinoButton(
          padding: EdgeInsets.zero,
          minimumSize: Size.zero,
          onPressed: _saving ? null : () => Navigator.of(context).pop(false),
          child: const AppText.body('Отмена', color: AppColors.accent),
        ),
      ),
      child: SafeArea(
        child: ListView(
          padding: const EdgeInsets.only(top: AppSpacing.s4, bottom: AppSpacing.s6),
          children: [
            AppCard(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  const AppText.footnote('Сумма'),
                  const SizedBox(height: AppSpacing.s1),
                  CupertinoTextField.borderless(
                    controller: _amountController,
                    autofocus: true,
                    placeholder: '0',
                    keyboardType: const TextInputType.numberWithOptions(decimal: true),
                    style: AppTypography.largeTitle.copyWith(
                      color: AppColors.of(context, AppColors.label),
                    ),
                    placeholderStyle: AppTypography.largeTitle.copyWith(
                      color: AppColors.of(context, AppColors.tertiaryLabel),
                    ),
                    padding: EdgeInsets.zero,
                    suffix: const AppText.title('₽', color: AppColors.secondaryLabel),
                    onChanged: (_) => setState(() => _error = null),
                    onSubmitted: (_) => _submit(),
                  ),
                  if (widget.remainingToday != null) ...[
                    const SizedBox(height: AppSpacing.s2),
                    AppText.footnote(
                      'На сегодня осталось ${formatMoney(widget.remainingToday!)}',
                      color: widget.remainingToday! < 0
                          ? AppColors.systemRed
                          : AppColors.secondaryLabel,
                    ),
                  ],
                ],
              ),
            ),
            const SizedBox(height: AppSpacing.s3),
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: AppSpacing.gutter),
              child: Row(
                children: [
                  for (final amount in _quickAmounts) ...[
                    AppChip(
                      label: formatMoney(amount, compact: true),
                      onPressed: () => setState(() {
                        _amountController.text = amount.toStringAsFixed(0);
                        _error = null;
                      }),
                    ),
                    const SizedBox(width: AppSpacing.s2),
                  ],
                ],
              ),
            ),
            const SizedBox(height: AppSpacing.s5),
            AppListSection(
              children: [
                AppListTile(
                  title: 'Дата',
                  value: formatRelativeDay(_date),
                  onTap: _saving ? null : _pickDate,
                ),
              ],
            ),
            const SizedBox(height: AppSpacing.s4),
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: AppSpacing.gutter),
              child: AppTextField(
                controller: _noteController,
                placeholder: 'Комментарий',
                prefixIcon: CupertinoIcons.text_alignleft,
                enabled: !_saving,
              ),
            ),
            if (_error != null)
              Padding(
                padding: const EdgeInsets.fromLTRB(
                  AppSpacing.gutter,
                  AppSpacing.s3,
                  AppSpacing.gutter,
                  0,
                ),
                child: AppText.footnote(_error!, color: AppColors.systemRed),
              ),
            const SizedBox(height: AppSpacing.s5),
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: AppSpacing.gutter),
              child: AppButton(
                label: 'Записать трату',
                loading: _saving,
                onPressed: _submit,
              ),
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _pickDate() async {
    final picked = await showAppDatePicker(
      context: context,
      initialDate: _date,
      maximumDate: DateTime.now(),
    );
    if (picked != null && mounted) setState(() => _date = picked);
  }
}